Electrochemical lithium insertion in the solid solution Bi2WO6-Sb2WO6 with Aurivillius framework

Following the structural evolution of the Aurivillius crystalline framework in the solid solution Bi₂WO₆-Sb₂WO₆ we have carried out an electrochemical lithium insertion study in this system. A slight loss of the specific capacity of the electrochemical cell was observed as amount of Sb was increased. In general, the different compositions within solid solution Bi_2−xSb_xWO₆ (0.25 ≤ x ≤ 0.75) exhibited a similar behaviour featured mainly by two semiconstant potential regions located at 1.7 and 0.8 V versus Li⁺/Li^o. The oxide Sb₂WO₆ with Autivillius structure but without Bi was tested as cathode too. The maximum amount of lithium inserted, 13.5 lithium atoms per formula, is the same amount inserted in its homologous bismuth oxide Bi₂WO₆.